/*=========================================================================
 *
 *  Copyright Insight Software Consortium
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/

#include "itkLandmarkDisplacementFieldSource.h"
#include "itkImageFileWriter.h"
#include "itkSimpleFilterWatcher.h"

#include <fstream>
#include "itkTestingMacros.h"


int itkLandmarkDisplacementFieldSourceTest( int argc, char * argv[] )
{

  if( argc < 3 )
    {
    std::cerr << "Missing Parameters " << std::endl;
    std::cerr << "Usage: " << itkNameOfTestExecutableMacro(argv);
    std::cerr << " landmarksFile outputImage" << std::endl;
    return EXIT_FAILURE;
    }

  constexpr unsigned int Dimension = 2;
  using VectorComponentType = float;

  using VectorType = itk::Vector< VectorComponentType, Dimension >;

  using DisplacementFieldType = itk::Image< VectorType,  Dimension >;

  using FilterType = itk::LandmarkDisplacementFieldSource<DisplacementFieldType>;

  FilterType::Pointer filter = FilterType::New();

  itk::SimpleFilterWatcher watcher(filter);

  DisplacementFieldType::SpacingType spacing;
  spacing.Fill( 1.0 );

  DisplacementFieldType::PointType origin;
  origin.Fill( 0.0 );

  DisplacementFieldType::RegionType     region;
  DisplacementFieldType::SizeType       size;
  DisplacementFieldType::IndexType      start;

  size[0] = 128;
  size[1] = 128;

  start[0] = 0;
  start[1] = 0;

  region.SetSize( size );
  region.SetIndex( start );

  DisplacementFieldType::DirectionType direction;
  direction.SetIdentity();


  filter->SetOutputSpacing( spacing );
  filter->SetOutputOrigin( origin );
  filter->SetOutputRegion( region );
  filter->SetOutputDirection( direction );

  //  Create source and target landmarks.
  //
  using LandmarkContainerType = FilterType::LandmarkContainer;
  using LandmarkPointType = FilterType::LandmarkPointType;

  LandmarkContainerType::Pointer sourceLandmarks = LandmarkContainerType::New();
  LandmarkContainerType::Pointer targetLandmarks = LandmarkContainerType::New();

  LandmarkPointType sourcePoint;
  LandmarkPointType targetPoint;

  std::ifstream pointsFile;
  pointsFile.open( argv[1] );

  unsigned int pointId = 0;

  pointsFile >> sourcePoint;
  pointsFile >> targetPoint;

  while( !pointsFile.fail() )
    {
    sourceLandmarks->InsertElement( pointId, sourcePoint );
    targetLandmarks->InsertElement( pointId, targetPoint );
    pointId++;

    std::cout << sourcePoint << "  -->> " << targetPoint << std::endl;

    pointsFile >> sourcePoint;
    pointsFile >> targetPoint;

    }

  pointsFile.close();


  filter->SetSourceLandmarks( sourceLandmarks );
  filter->SetTargetLandmarks( targetLandmarks );

  try
    {
    filter->UpdateLargestPossibleRegion();
    }
  catch( itk::ExceptionObject & excp )
    {
    std::cerr << "Exception thrown " << std::endl;
    std::cerr << excp << std::endl;
    }

  // Write an image for regression testing
  using WriterType = itk::ImageFileWriter<  DisplacementFieldType  >;

  WriterType::Pointer writer = WriterType::New();

  writer->SetInput (filter->GetOutput());
  writer->SetFileName( argv[2] );

  try
    {
    writer->Update();
    }
  catch( itk::ExceptionObject & excp )
    {
    std::cerr << "Exception thrown by writer" << std::endl;
    std::cerr << excp << std::endl;
    return EXIT_FAILURE;
    }

  return EXIT_SUCCESS;

}
